any brain tumor that develops in a limited space of the skull, as it grows, leads to a conflict incompatible with life — compression of the brain, disruption of its function and death of the patient. In this regard, the generally accepted concepts of benign or malignant tumor relative to the brain have a conditional meaning.
Other features that lead to a typical course of CNS tumor diseases are the blood-brain barrier, which restricts the penetration of many substances (including drugs) from the blood into the brain tissue, and a certain immune privilege of the CNS.
The principles of radical, ablastic removal of CNS tumors, especially those developing from the brain tissue itself, are impracticable in most cases.
These and a number of other features determine the uniqueness of therapeutic approaches in CNS oncological diseases.